Transverse connectors

ABSTRACT

Devices and methods are disclosed for treating the vertebral column. One embodiment provides a transverse connector for vertebral fixation systems comprising a first connector body comprising a first engaging member for engaging a first elongate member and a first locking member, a second connector body comprising a second engaging member for engaging a second elongate member, and a transverse rod coupled to the first connector body and the second connector body, thereby forming an articulation between a first end of the transverse rod and the first connector body, wherein the first locking member is configured to secure both the articulation and the first elongate member to the first connector body.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. §119(e) to U.S.Provisional Application No. 61/172,116 filed on Apr. 23, 2009, thedisclosure of which is incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to transverse connectors used inspinal fixation systems. The invention comprises assemblies that arecoupled to spinal rods, plates, or other elongate members to providestability to a construct. The invention may be configured so thatmultiple transverse connectors may be used along the vertebral column.

2. Description of the Related Art

Advancing age, as well as injury, can lead to degenerative changes inthe bones, discs, joints and ligaments of the spine, producing pain andinstability. Under certain circumstances, alleviation of the problemscan be provided by performing spinal fusion. Spinal fusion is a surgicaltechnique where two or more vertebrae of the spinal column are fusedtogether to eliminate the motion between the fused vertebrae. Spinalfusion is used to treat conditions where the spine exhibits instability.Spine instability may result from causes such as fracture, scoliosis andspondylolisthesis, where one or more vertebrae move in a forwarddirection relative to the other vertebrae. Spinal fusion with discectomyis also performed for herniations of the discs. This surgery involvesremoval of the affected disc and fusion of the adjacent vertebrae.Traditionally, bone grafts have been used to fuse the vertebrae, butvarious types of vertebral implants have also been used.

The use of fixation systems for achieving spinal fusion is wellestablished. One of the more common fixation systems is the pediclescrew fixation system. In this fixation system, pedicle screws areinserted into two or more vertebrae and interconnected with a rod orother elongate member. The screws are rigidly connected to the elongatemember so that the fixation system greatly reduces motion between theadjoining vertebrae. Multiple fixation systems may be utilized toachieve greater strength and stability. Other types of fixation systemsuse different vertebrae attachment devices, including but not limitedto, transverse process hooks, sublaminar hooks, pedicle hooks, fixationplates and other similar devices.

It is well known in the art that coupling multiple fixation systems witha transverse connector also increases strength and stability of theassembly. A transverse connector is used to span the distance betweentwo elongate members. Ideally, the fixation system is implanted in thebody so that the two elongate members are substantially parallel to eachother in a single plane. This permits the use of a simple transverseconnector that need only be adjustable in length, along its longitudinalaxis. However, due to variations in body geometries and implantinginconsistencies, the elongate members are rarely parallel in practice.The elongate members may be co-planar but not parallel, or may not beco-planar, or both not co-planar nor parallel. In the past, this problemwas addressed by forcefully bending the elongate members or thetransverse connector to accommodate for the misalignment of the elongatemembers. This solution is not optimal because it introducesmisalignments that possibly compromise the strength and stability of theassembly. Additionally, it could weaken the mechanical properties of theelongate member or the transverse connector.

Prior inventions addressed this problem through the use of a transverseconnector with greater adjustability. U.S. Pat. No. 5,980,523 disclosesa transverse connector with separable pieces that are assembled togetherwith separate screw fasteners to accommodate for non-parallel elongatemembers. The disadvantage with this invention is the number of separablepieces, which are difficult to assemble in the clinical environment,especially considering the miniature sizes of some of the pieces.Surgeons may also risk losing pieces within the patient's body cavityduring implantation.

Further advancements solved this problem with the invention of aone-piece transverse connector, but there still remains someshortcomings. For example, U.S. Pat. No. 6,736,817 discloses a one-piecetransverse connector that is adjustable for convergent or divergentelongate members, non-coplanar elongate members, and variations indistances between elongate members. The adjustment for convergence ordivergence is accomplished through a joint placed between two couplinghooks that attach to elongate members. The joint comprises of two matingsurfaces, each with teeth that allows the two ends of the transverseconnector to hinge with respect to each other at various angles. Thehinge joint is locked with a screw fastener. However, the disadvantageof this design is the complexity of the additional screw. The addedscrew introduces an additional component for possible failure or usererror. Also, the additional weight and bulk of the hinge joint isanother drawback of the design. The vertebral fixation assembly may beplaced in the human body for extended periods of time. Any tinyadditional weight or bulk of the fixation assembly can translate intogreater discomfort for the patient. Thus, it is advantageous for thevertebral fixation assembly to be as compact as possible to minimize itsintrusion in the body.

As a consequence of the foregoing, there remains a need for improvedadjustable transverse connectors with simple, compact adjustments.

SUMMARY OF THE INVENTION

The present invention relates generally to transverse connectors used inspinal fixation systems.

One embodiment provides a transverse connector for vertebral fixationsystems comprising a first connector body comprising a first engagingmember for engaging a first elongate member and a first locking member,a second connector body comprising a second engaging member for engaginga second elongate member, and a transverse rod coupled to the firstconnector body and the second connector body, thereby forming anarticulation between a first end of the transverse rod and the firstconnector body, wherein the first locking member is configured to secureboth the articulation and the first elongate member to the firstconnector body.

The above embodiments and methods of use are explained in more detailbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and method of using the invention will be betterunderstood with the following detailed description of embodiments of theinvention, along with the accompanying illustrations, in which:

FIG. 1 is a lateral elevational view of a portion of the vertebralcolumn.

FIGS. 2A and 2B are superior and lateral elevational views of a thoracicvertebra.

FIG. 3 illustrates a superior elevational view of a cervical vertebra.

FIG. 4 represents a superior elevational view of a lumbar vertebra.

FIG. 5 is a top plan view of one embodiment of a vertebral fixationassembly.

FIG. 6 is a top perspective view of one embodiment of an adjustabletransverse connector.

FIG. 7 is an exploded view of one embodiment of a rod connector with anarticulation and a first locking member.

FIG. 8 is a cross-sectional view of one embodiment of an adjustabletransverse connector showing a rod connector with a second lockingmember and a transverse rod with a third locking member.

FIG. 9 is a cross-sectional exploded view of one embodiment of aslideable and rotational transverse rod with a third locking member.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Advancing age, as well as injury, can lead to degeneration in the bones,discs, joints, and ligaments of the spine producing pain from nerve rootcompression. Under certain circumstances, alleviation of pain can beprovided by performing a spinal fusion. Spinal fusion is a procedurethat involves joining two or more adjacent vertebrae so that they nolonger are able to move relative to each other.

A. Anatomy of the Spine

As shown in FIG. 1, the vertebral column 2 comprises a series ofalternating vertebrae 4 and fibrous discs 6 that provide axial supportand movement to the upper portions of the body. The vertebral column 2typically comprises thirty-three vertebrae 4, with seven cervical(C1-C7), twelve thoracic (T1-T12), five lumbar (L1-L5), five fusedsacral (S1-S5) and four fused coccygeal vertebrae. FIGS. 2A and 2Bdepict a typical thoracic vertebra. Each vertebra includes an anteriorbody 8 with a posterior arch 10. The posterior arch 10 comprises twopedicles 12 and two laminae 14 that join posteriorly to form a spinousprocess 16. Projecting from each side of the posterior arch 10 is atransverse 18, superior 20 and inferior articular process 22. The facets24, 26 of the superior 20 and inferior articular processes 22 form facetjoints 28 with the articular processes of the adjacent vertebrae.

The typical cervical vertebrae 30, shown in FIG. 3, differ from theother vertebrae with relatively larger spinal canals 32, oval shapedvertebral bodies 34, bifid spinous processes 36 and foramina 38 in theirtransverse processes 40. These foramina transversaria 38 contain thevertebral artery and vein. The first and second cervical vertebrae alsofurther differentiated from the other vertebrae. The first cervicalvertebra lacks a vertebral body and instead contains an anteriortubercle. Its superior articular facets articulate with the occipitalcondyles of the skull and are oriented in a roughly parasagittal plane.The cranium is able to slide forward and backwards on this vertebra. Thesecond cervical vertebra contains an odontoid process, or dens, whichprojects superiorly from its body. It articulates with the anteriortubercle of the atlas, forming a pivot joint. Side to side movements ofthe head occur at this joint. The seventh cervical vertebra is sometimesconsidered atypical since it lacks a bifid spinous process.

Referring to FIG. 4, the typical lumbar vertebrae 42 is distinguishablefrom the other vertebrae by the absence of foramina transversaria andthe absence of facets on the surface of the vertebral body 44. Thelumbar vertebral bodies 44 are larger than the thoracic vertebral bodiesand have thicker pedicles 46 and laminae 48 projecting posteriorly. Thevertebral foramen 50 is triangular in shape and larger than the foraminain the thoracic spine but smaller than the foramina in the cervicalspine. The superior 52 and inferior articular processes (not shown)project superiorly and inferiorly from the pedicles, respectively.

B. Transverse Connector

FIG. 5 shows one embodiment of a vertebral fixation system 55,comprising a transverse connector 53 connecting a first elongate member54 and a second elongate member 56. In some embodiments, the elongatemembers 54 and 56 are coupled to the vertebral column using attachmentdevices, such as pedicle screws. For example, a first pedicle screw 60may be attached to a pedicle of a first vertebra and a second pediclescrew 61 may be attached to a pedicle of a second vertebra. Althoughdepicted as pedicle screws in FIG. 5, the means for coupling theelongate members 54 and 56 to the vertebral column can be any attachmentdevice that can couple an elongate member to a vertebra. For example, inother embodiments, the attachment devices may be hooks, clamps or otherfastening device. The elongate member may be any rigid member capable ofcoupling to and stabilizing the vertebral column, such as a spinal rod.In some embodiments, the elongate members 54 and 56 may be rectangularbars, polygonal bars, I-beams, or any other device suitable forconnecting the pedicle screws.

The two elongate members are coupled to each other using a transverseconnector 53. In some embodiments, the transverse connector hasgenerally a curved shape to allow for the posterior arch of thevertebral column. The transverse connector 53 can be comprised of anymaterial that is suitable for orthopedic applications, such as titanium,stainless steel, metal alloys, plastics, or other material compatiblefor use in the body. FIG. 6 shows one embodiment of the transverseconnector 53, which comprises a first connector body 62 coupled to asecond connector body 66 via a transverse rod 64. The transverse rod 64comprises an end with a pivot joint 73 and a projection end 75. The endwith a pivot joint 73 is configured to couple to the first connectorbody 62, thereby forming an articulation between the first connectorbody 62 and the transverse rod 64. The projection end 75 of thetransverse rod 64 is configured to couple to the second connector body66. The transverse connector 53 spans the distance between two elongatemembers and may be used to add stability, such as torsional stability,to the vertebral fixation system 55. In some embodiments, the transverseconnector 53 is adjustable in length and can adapt for multi axialrotational differences in the orientations of the elongate members.

The first connector body 62 comprises a first locking member 63 and afirst engaging member 68. In some embodiments, the first connector body62 further comprises a pushing member 71. As shown in FIG. 7, in someembodiments, the first connector body 62 comprises a first engagingmember 68 toward one end for engaging the first elongate member 54 tothe first connector body 62. The first connector body 62 also comprisesa through bore 57 from a first surface of the connector body to a secondsurface of the connector body, wherein the second surface of theconnector body is adjacent to the first engaging member 68. The throughbore 57 houses the first locking member, which comprises a first lockingnut 70 for securing an elongate member within the first engaging member68.

In some embodiments, the first engaging member 68 may be a hooked endconfigured to accept an elongate member such as a spinal rod. In otherembodiments, the first engaging member 68 may have a different designthat is compatible with other types of elongate members, such aspolygonal bars or I-beams. In some embodiments, the first locking nut 70can secure the elongate member by pushing the elongate member againstthe first engaging member 68.

In some embodiments, the first locking member 63 may further comprise afirst contacting saddle 69 configured to make contact with and secure anelongate member in the first engaging member 68. In some embodiments,the surface 69 a of the first contacting saddle 69 that contacts thefirst locking nut 70 has a helical surface, which corresponds with thehelical surface on the bottom surface 70 b of the first locking nut 70.In other embodiments, the complimentary surfaces are contours other thanhelical. In some embodiments, turning the first locking nut 70 may causethe contacting saddle 69 b to push down on the elongate member, therebysecuring the elongate member to the first connector body 62 in theengaging member 68.

In some embodiments, the first locking member 63 is configured to secureboth the articulation (i.e., lock the pivot joint 73 of the transverserod 64) and the first elongate member 54 to the first connector body 62.The first connector body 62 may also comprise a passage 72 that has oneopening toward the medial end and the other opening in the through bore57. The passage 72 houses the pushing member 71 and the pivot joint endof the transverse rod 64. In some embodiments, the pivot joint 73comprises a cylindrical shape with a longitudinal axis 74 that isgenerally perpendicular to the longitudinal axis 58 of the transverserod 64. The projection end 75 extends out from the medial opening of thepassage 72 in the first connector body 62. In some embodiments, themedial opening of the passage 72 is configured to permit the transverserod 64 to pivot at the pivot joint 73 about the longitudinal axis 74 ofthe pivot joint when the first locking member 63 is in an unlockedposition, creating an angle α measured between the longitudinal axis 58of the transverse rod 64 and the longitudinal axis 59 of the firstconnector body 62, as illustrated in FIG. 5. For example, the medialopening may be larger than the diameter of the transverse rod 64,particularly in the lateral directions, to allow the transverse rod 64to swing from one side to the other along the defined plane. Thispivoting movement allows the transverse connector 53 to adjust forconvergence or divergence of the implanted elongate members 54 and 56.In some embodiments, the pivot joint 73 may comprise otherconfigurations that permit the transverse rod 64 to pivot along adifferent plane.

In some embodiments, the pushing member 71 can be coupled to both thepivot joint 73 of the transverse rod 64 within the passage 72 and thefirst locking nut 70 through the opening in the through bore 57. In someembodiments, the surface of the pushing member 71 that contacts thefirst locking nut 70 can have a helical surface complimentary to thesecond helical surface on the first locking nut 70. The helical surfacescan be configured so that as the locking nut 70 is turned to the lockposition, the pushing member 71 pushes the pivot joint 73 up andmedially to lock the pivot joint 73 against the interior wall of thepassage 72 in the first connector body 62. In other embodiments, thecomplimentary surfaces can be contours other than helical.

For example, in some embodiments, the first locking nut 70 can have acam surface disposed on the outer cylindrical surface 70 c which coupleswith the pushing member 71. The cam surface can have a radial gradientwherein the radius of the cam surface can increase from one side of thecam surface to the other side of the cam surface. When the first lockingnut 70 is rotated, the increasing radius of the cam surface can push thepushing member 71 in the medial direction, thereby translatingrotational motion of the first locking nut 70 into linear movement ofthe pushing member 71.

The pushing member 71 can have a generally trapezoidal wedgeconfiguration with coupling surfaces for the first locking nut 70 andthe pivot joint 73. In some embodiments, the pushing member 71 can havea slot disposed along the lateral direction that extends from the top ofthe pushing member 71 down to a partial height of the pushing member 71.When the first locking nut 70 biases the pushing member 71 against thepivot joint 73, the slotted pushing member 71 can partially deform toprovide a spring force to the pivot joint 73. In other embodiments, theslot in the pushing member 71 can be omitted.

In some embodiments, the pivot joint 73 can have a roughened surface onat least a portion of its surface that contacts a complimentary surfaceon the first connector body 62 when the first locking nut 70 istightened or in the locked position. Some examples of the roughenedsurface include, but are not limited to teeth, ridges, or abrasivesurfaces. When the first locking nut 70 is tightened or locked, thetransverse rod 64 is fixed and can no longer pivot along the definedplane.

In some embodiments, the pivot joint 73 can comprise elongate teeth orgrooves that are disposed along the longitudinal axis 74 on at least aportion of the cylindrical surfaces that contacts the first connectorbody 62. The first connector body 62 can comprise a complimentarysurface with elongate teeth or grooves that can couple with the elongateteeth or grooves on the pivot joint 73 to restrict the pivotal movementof the transverse rod 64. In other embodiments, the elongate teeth orgrooves may be omitted from the pivot joint 73.

As shown in FIG. 8, the second connector body 66 comprises a secondlocking member 67, a third locking member 65 and a second engagingmember 82. The second connector body 66 comprises a receiving bore 80that has an opening at the medial end of the second connector body 66.The receiving bore 80 is configured to receive the projection end 75 ofthe transverse rod 64, which allows the second connector body 66 toslide along generally the longitudinal axis 58 of the transverse rod 64to account for variations in implanted distances of elongate members 54and 56. In some embodiments, the second connector body 66 can alsorotate generally about the longitudinal axis 58 to account fornon-parallel and/or non co-planar elongate members 54 and 56.

In some embodiments, the transverse rod 64 is allowed to slide in andout of the receiving bore 80 along generally the longitudinal axis 58 ofthe transverse rod 64 so as to lengthen and shorten the overall lengthof the transverse connector 53. In some embodiments, the transverse rod64 may also rotate within the receiving bore 80 generally about thelongitudinal axis 58. In some embodiments, the transverse rod 64 furthercomprises a retaining pin 77 toward the end of the projection end 75 asshown in FIG. 8. The retaining pin 77 serves to stop the transverse rod64 from sliding out of the receiving bore 80 completely and limits therotation of the transverse rod 64 within the receiving bore 80 aboutaxis 58. As an inseparable piece, the transverse connector 53 is easierto handle and to implant without having to account for several smallpieces.

With reference to FIGS. 8 and 9, in some embodiments, the retaining pin77 may be engaged in a groove 81 located on the underside of the secondconnector body 66. In some embodiments, the groove 81 is an elongatedcutout that is large enough to allow the movement of the retaining pin77 when the transverse rod 64 slides and rotates inside of the receivingbore 80. In some embodiments, the groove 81 may also be a recess withina portion of the receiving bore that is large enough to accommodateretaining pin 77 movements. The angle of rotation allowed by the groove81 is labeled as β in FIG. 9. In some embodiments, about a 90 degreefreedom of rotation of the transverse rod 64 is sufficient to accountfor angular variations of non-parallel connector rods in the usualclinical environment. However, groove sizes that allow for less or morethan 90 degrees of rotation of the transverse rod 64 may be appropriatefor some situations.

The second connector body 66 also comprises a first through bore from afirst surface of the connector body to a second surface of the connectorbody, wherein the opening of the second through bore on the secondsurface of the connector body is adjacent to the second engaging member82. The first through bore of the second connector body 66 houses thesecond locking member 67, which comprises a second locking nut 79 forsecuring a second elongate member 56 within the second engaging member82.

In some embodiments, the second engaging member 82 may be a hooked endconfigured to accept an elongate member such as a spinal rod. In otherembodiments, the second engaging member 82 may have a different designthat is compatible with other types of elongate members, such aspolygonal bars or I-beams. In some embodiments, the second locking nut79 can secure the second elongate member 56 by pushing the elongatemember against the second engaging member 82.

In some embodiments, the second locking member 67 may further comprise asecond contacting saddle 78 configured to make contact with and securethe second elongate member 56 in the second engaging member 82. Thesurface of the second contacting saddle 78 that contacts the secondlocking nut 79 has a helical surface, which is complimentary to thehelical surface on the bottom surface of the second locking nut 79. Inother embodiments, the complimentary surfaces are contours other thanhelical. In some embodiments, turning the second locking nut 79 to alocked position may cause the contacting saddle 78 to push down on thesecond elongate member 56, thereby securing the second elongate member56 to the second connector body 66 in the second engaging member 82.

With reference to FIGS. 6, 8 and 9, the second connector body 66 furthercomprises a second through bore 85 from the first surface of theconnector body to the receiving bore 80 at the medial end of the secondconnector body 66. The second through bore 85 of the second connectorbody 66 houses the third locking member 65. The third locking member 65comprises a third locking nut 83, which is configured to secure thetransverse rod 64 to the second connector body 66. Once the length andaxial rotation of the transverse rod 64 are positioned within thereceiving bore 80, the transverse rod 64 can be locked by tightening thethird locking nut 83.

In some embodiments, the third locking member 65 may further comprise atransverse rod contacting saddle 84. In some embodiments, the thirdlocking nut 83 is a cylindrical body with a helical surface on its outercylindrical wall which, when tightened or locked, contacts acomplimentary helical surface on the second connector body 66 causingthe third locking nut 83 to apply pressure against the transverse rodcontacting saddle 84, which in turn applies pressure to the transverserod 64, locking it in place. In other embodiments, the complimentarysurfaces are contours other than helical. In some embodiments, thetransverse rod contacting saddle 84 is a cylindrical body with a concavesurface on one end for accepting and locking the transverse rod 64 in afixed position and a flat surface on the other end for mating with thebottom flat surface of the third locking nut 83. In other embodiments,the transverse rod contacting saddle 84 may be omitted and the thirdlocking nut 83 can be in contact with the transverse rod 64. The thirdlocking nut 83 can apply pressure directly to the transverse rod 64. Insome embodiments, the bottom surface of the third locking nut 83 can bespherically concave to optimize contact area with the curved transverserod 64.

In some embodiments, the top 70 a of at least one of the locking nutscomprise a mating surface for accepting common tools, such as Allenwrench, screwdrivers, or any other common tool. In other embodiments, atleast one locking nuts comprise a special mating surface on top that canonly be operated by a special tool. In some embodiments, one or more ofthe contacting saddles may comprise a stem extending from the topportion 69 a. In these embodiments, the corresponding locking nut wouldhave a hole to accommodate the protruding stem on the contacting saddle,so the contacting saddle is properly lined up with the correspondinglocking nut. In some embodiments, the configurations of the locking nutsand the contacting saddles may be interchangeable. For example, thecomplimentary helical surfaces may be on the outer cylindrical wall 70 cof the locking nut and the connector body in one embodiment. In anotherembodiment, the complimentary helical surfaces may be on the bottom 70 bof the locking nut and the top 69 a of the corresponding contactingsaddle. In some embodiments, at least one of the locking nuts and/orcontacting saddles may have a different configuration compared to theothers.

C. Implantation Procedure

In some embodiments of the invention, the patient is intubated andgeneral anesthesia is achieved. The patient is prepped and draped in theusual sterile fashion. A posterior approach to the spine is used toexpose the posterior vertebral bodies. Many posterior approaches to thevertebral column are described in various medical texts such asCampbell's Operative Orthopaedics, 10th ed., edited by Canale et al.,herein incorporated by reference. In some embodiments, the uppercervical spine is accessed. In other embodiments, the lower cervicalspine, cervicothoracic junction, thoracic spine, thoracolumbar junction,lumbar region, lumbosacral junction, sacrum or combination of the aboveregions are accessed.

The vertebral column is accessed and one or more vertebrae areidentified and accessed. In some embodiments, two or more vertebrae areaccessed and in still other embodiments, two or more adjacent vertebraeare accessed. A pedicle screw, hook, anchor or other attachment deviceis attached to a first vertebra. A second attachment device is attachedto a second vertebra. The two attachment devices are coupled with afirst elongate member 54. In some cases, a second set of attachmentdevices is then attached to the same vertebrae on the other side of theposterior arch. In other cases, the second set of attachment devices canbe attached to different vertebrae. A second elongate member 56 is thenused to couple the second set of attachment devices. In some cases, thetwo elongate members 54, 56 are generally parallel to each other. Inother cases, the two elongate members 54, 56 may be at an angle to eachother or unleveled.

A transverse connector 53, such as one of the embodiments disclosed inthe present application, is positioned between the two elongate members54, 56. The transverse connector 53 can be bent at the articulationbetween the first connector body 62 and the transverse rod 64 tocompensate for convergence or divergence between the two elongatemembers 54, 56. The projection end 75 of the transverse rod 64 can berotated within the receiving bore 80 in the second connector body 66 tocompensate for the differences in angular orientations of the twoelongate members 54, 56 with respect to coronal plane. The transverserod 64 can also be slideably moved in and out of the receiving bore 80for adjusting the bridging distance between the two elongate members 54,56.

After adjustments are made to properly seat the elongate members 54, 56into the engaging members 68, 82 of the transverse connector 53, thefirst and the second locking members 63, 67 are tightened to secure theelongate members 54, 56 to the transverse connector 53. At the sametime, the articulation between the first connector body 62 and thetransverse rod 64 is also secured or locked at the set angle. The thirdlocking member 65 is also tightened to secure the transverse rod 64 tothe second connector body 66 and to lock down the rotational and thesliding movements, so the longitudinal length of the transverseconnector 53 and the angular orientation of the two connector bodies arefixed. Lastly, the operative site is irrigated with antibiotics and theoperative field is sutured closed.

Although the present invention has been described in relation to variousexemplary embodiments, various additional embodiments and alterations tothe described embodiments are contemplated within the scope of theinvention. Thus, no part of the foregoing description should beinterpreted to limit the scope of the invention as set forth in thefollowing claims. For all of the embodiments described above, the stepsof the methods need not be performed sequentially.

What is claimed is:
 1. A transverse connector for vertebral fixationsystems comprising: a first end, a second end, and a center, the firstand second ends of the transverse connector are configured to be locatedon first and second lateral sides of a vertebral column and the centerof the transverse connector is medial relative to the first and secondends; a first connector body comprising a first hooked end at a lateralend of the first connector body for engaging a first elongate member, afirst locking member, a through bore that houses the first lockingmember, the through bore located medial to the first engaging member, apassage having a first opening in a medial end of the through bore and asecond opening at a medial end of the first connector body, and apushing member housed in the passage such that a lateral surface of thepushing member contacts the first locking member through the firstopening; a second connector body comprising a second engaging member forengaging a second elongate member; a transverse rod coupled to the firstconnector body and the second connector body; and a pivot joint disposedon a first end of the transverse rod and configured to couple with thefirst connector body wherein the pivot joint comprises a cylindricalshape with a longitudinal axis generally perpendicular to a longitudinalaxis of the transverse rod and is housed in the connector body passage,wherein the first locking member comprises a first locking nut with atop surface, a bottom surface, and an outer cylindrical surface, and afirst contacting saddle with a top surface which corresponds to thebottom surface of the first locking nut and a bottom surface whichcorresponds to a surface of the first elongate member; wherein the firstlocking member has a locked position and an unlocked position, whereinin the unlocked position the transverse rod may pivot at the pivot jointabout the longitudinal axis of the pivot joint in a defined plane, andwherein in the locked position, the first locking member is configuredsuch that the outer cylindrical surface of the locking nut pushes thepushing member medially to lock the pivot joint against the medial endof the first connector body and such that the bottom surface of thelocking nut pushes on the contacting saddle such that the bottom surfaceof the contacting saddle pushes the first elongate member against thefirst hooked end of the first connector body.
 2. The transverseconnector of claim 1, wherein the passage is configured to receive thepivot joint on the first end of the transverse rod through the secondopening at the medial end of the first connector body to form anarticulation between the transverse rod and the first connector body. 3.The transverse connector of claim 1, wherein the outer, cylindricalsurface of the first locking nut comprises a cam surface.
 4. Thetransverse connector of claim 1, wherein the second connector bodyfurther comprises a receiving bore configured to receive a projectionend of the transverse rod.
 5. The transverse connector of claim 4,wherein the transverse rod can slideably move in and out of thereceiving bore along a longitudinal axis and rotate about thelongitudinal axis.
 6. The transverse connector of claim 4, wherein thesecond connector body further comprises a second locking memberconfigured to secure the second elongate member to the second connectorbody, and a third locking member configured to secure the projection endof the transverse rod to the second connector body.
 7. The transverseconnector of claim 6, wherein the second locking member comprises asecond locking nut, and a second contacting saddle configured to contactand secure the second elongate member to the second connector body whenthe second locking member is in a locked position.
 8. The transverseconnector of claim 1, wherein the transverse rod further comprises aretaining pin at a projection end.
 9. The transverse connector of claim8, wherein the second connector body further comprises a groove, whereinthe retaining pin is engaged within the groove.
 10. The transverseconnector of claim 1, wherein the transverse connector has generally acurved shape to allow for the posterior arch of the vertebral column.11. The transverse connector of claim 1, wherein at least one of thefirst and the second connector bodies is a rod connector.
 12. Thetransverse connector of claim 1, wherein the second engaging membercomprises a hook end.
 13. The transverse connector of claim 1, furthercomprising: a coupling surface on a portion of the pivot joint; and acomplimentary coupling surface on a portion of the first connector body;wherein, when the coupling surfaces are coupled, the transverse rod andthe first connector body maintain an angular orientation in relation toeach other.
 14. The transverse connector of claim 13, wherein thecoupling surfaces comprise abrasive surfaces.
 15. A method of implantinga vertebral fixation device, the method comprising the steps of:coupling a first connector body of a transverse connector with a firstelongate member, wherein the transverse connector comprises a firstlateral end, a second lateral end, and a medial central portion, andwherein the first connector body comprises a lateral end, a medial endand a middle portion; positioning a transverse rod comprising an endwith a pivot joint and a projection end such that a longitudinal axis ofthe transverse rod is in angular relation to a longitudinal axis of thefirst connector body by pivoting at the pivot joint along a definedplane; and actuating a first locking member with a top surface, a bottomsurface, and an outer cylindrical surface to secure both the transverserod to the medial end of the first connector body by the outercylindrical surface pushing medially on a pushing member which pushesthe transverse rod against the medial end of the first connector body,and the lateral end of the first connector body to the first elongatemember by the bottom surface pushing on the first elongate member. 16.The method of implanting a vertebral fixation device of claim 15,further comprising the steps of: coupling a second connector body of thetransverse connector with a second elongate member before actuating thefirst locking member; actuating a second locking member to secure thesecond connector body with the second elongate member.
 17. The method ofimplanting a vertebral fixation device of claim 15, further comprisingthe steps of: positioning the transverse rod in relation to the secondconnector body by sliding the transverse rod in or out of the secondconnector body and/or by rotating the transverse rod about alongitudinal axis of the transverse rod; actuating a third lockingmember to secure the transverse rod to the second connector body.